AI agents invoke execute_sql_query to trigger actions in Supabase MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.
While the tool includes validation and the server description mentions "built-in safety controls," SQL query execution is fundamentally an Execute category tool. It can trigger external database operations whose effects depend on the SQL arguments provided. The validation mentioned may mitigate risk but does not change the core capability.
From the tool's definition Tool is named "execute_sql_query" and described as "Execute an SQL query with validation." The description explicitly states it executes SQL, which can run arbitrary queries including data modification, deletion, or execution of stored procedures depending on…
Documented attack patterns abuse exactly the kind of access execute_sql_query gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Supabase MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for execute_sql_query:
{
"version": "1",
"default": "deny",
"tools": {
"execute_sql_query": {
"limits": [
{
"counter": "execute_sql_query_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}execute_sql_query stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Execute an SQL query with validation. It is categorised as a Execute tool in the Supabase MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Supabase MCP Server MCP server in PolicyLayer and add a rule for execute_sql_query: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Supabase MCP Server. Nothing to install.
execute_sql_query is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the execute_sql_query rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for execute_sql_query. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
execute_sql_query is provided by the Supabase MCP Server MCP server (deploya-labs/mcp-supabase). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Supabase MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
10 Supabase MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.